Abstract：Abstract Objective To provide the pathogenic fungi causing Orah leaf spot disease, and the mangroves actinomycete strains against pathogenic fungi to prevent and control Orah fungal disease. Methods The pathogens were isolated and purified from Orah leaves and further identified by morphological observation and ITS sequence analysis coupling with the phylogenetic tree. The pathogenicity was verified according to Koch’s rule with healthy Orah leaves. Twenty-four actinomycetes isolated from mangrove soil were used to screen inhibitory activity against plant pathogenetic fungi by plate confrontation method. The antifungal and disease prevention effects of the fermentation products from representative strains were tested. The genome sequence of the target strain was analyzed by antiSMASH to evaluate the biosynthetic potential of secondary metabolites. Results Pathogenicity was confirmed by inoculating these four kinds of fungi on healthy Orah leaves, as a result, the symptoms of leaf spot appeared by infection of Boeremia exigua and Fusarium solani. Streptomyces strain M2020 showed good antifungal activities against four different plant pathogenic fungi, and its fermentation products were effective in the control of Orah fungal diseases caused by fungal strain C4. A total of 38 secondary metabolite biosynthetic gene clusters for biosynthesis of Polyketides, Non-Ribosomal Polypeptides and Terpene, etc. were identified in the genome of strain M2020. Conclusion The pathogenic fungi causing Orah leaf spot disease are Boeremia exigua and Fusarium solani. The Streptomyces strain M2020 can be a good choice for a biological control of Orah leaf spot disease.
李菲1 杨玲2 王巧贞2 许秀松3,4 黄庶识2 杨慧欢5 覃仙玲1,*. 红树林放线菌抗沃柑病原真菌的研究[J]. 中国抗生素杂志, 2022, 47(07): 638-646.
Li Fei1, Yang Ling2, Wang Qiao-zhen2, Xu Xiu-song3,4, Huang Shu-zhi2, Yang Hui-huan5, and Qin Xian-ling1. Study on mangrove actinomycetes against pathogenetic fungi of Orah. CJA, 2022, 47(07): 638-646.
